Process of forming a tube.



H. M. BRIGHTMAN.

PROCESS OF FORMING A TUBE.

APPLICATION FILED MAYI2.'1916.

1 ,21 9,802. Patented Mar. 20, 1917.

HARRISON MBRIEHTMAN lzi yl mw HARRISON M. BRIGHTMAN', 0F COLUMBUS, OHIO.

PROCESS OF FORMING- A TUBE.

To all whom it may concern:

lie it known that I. HAmusoN M. BRIGHT- MAN, a citizen of the United States of America, residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Processes of Forming a Tube, of which the following isa specification.

The present invention is an improved process of forming a tube, and is one of several steps employed in the formation of a nut ready to be tapped, and the invention involves certain means by which a metal billet or bar is fashioned into a tube ready to be cut into pieces or completed nuts ready for tapping.

The primary object of the invention is to increase the rapidity with which the completed nuts for tapping are produced and to increase the strength, particularly of that portion of th metal to be tapped for the threads, thus providing for an enhanced quality and quantity in the production of the nuts.

In the accompanying drawings I have illustrated diagrammatically the means employed for the carrying out of the step of the improved process or method of my invention, arranged and related inthe best mode I have so far devised for the accomplishment of my invention;

The figure of the drawing is a side view partly in section of the revoluble frame with, its rollers, and mandrel for rolling the billet and piercing it to form a tube.

In the preferred embodiment of my invention I utilize a billet or bar 1, of metal of comparatively short length, and while hot the billet is pierced, longitudinally, from end to end leaving a bore of suitable area. The hot billet is pierced by means of the pointed mandrel 2 which is rotated as the billet is forced against its end and then caused to pass over the mandrel until the entire length of the billet is pierced.

Specification of Letters Patent.

Application filed May 12, 1916.

Patented Mar. 241*, 1917. Serial No. 97,066.

Various instrumentalities may be utilized for piercing the billet, and in the drawing one device is exemplified for this purpose. The frame 3 with its trunnions is caused to revolve bodily in its supports or standards 4 4, and the Hat driven disks 5, 5, which rotate in opposite directions according to the arrows. through the connection or train of gears 6, T, 8, roll and fashion the billet into a bar circular in cross section and of course solid as to transverse area. As the bar is forced past the flat disks, its front end encounters the rotating mandrel, the point of the mandrel pierces the end of the bar, and the continuous feed of the bar to the right in the direction of the arrow, causes the bar to be pierced. Coacting with the mandrel are a pair of concave rollers 9, 9, carried by the revolving frame, and disposed diametrically opposite each other in position to roll freely over the portion of the bar which is being enlarged at the point of penetration of the mandrel. In this manner the concave rollers perform the dual function of holding stable the billet as it is pierced and at the same time preserving with uniform regularity the circular cross sectional area of the bar as it is enlarged into the tubular bar 10, thus completing the first step in the process.

The blank or tubular bar 10 is now treated in suitable manner to reduce the tubular bar to its final cross sectional shape.

\Vhat I claim is The step in the art of forming a tube which consists in rolling abillet by bodily revolving about a billet oppositely rotated members in contact therewith, supporting the billet with rotating members bodily revolving in synchronism with the rotated members, and piercing the billet at its supported point to form the tubular structure.

In testimony whereof I aiiix my signature.

HARRISON M. BRIGHTMAN. 

